Currently, OLED panels have gradually dominated the display field due to the characteristics such as low power consumption, high color saturation, wide viewing angle, low thickness, no backlight and the like.
Evaporation technique is one of key techniques in the process of manufacturing an OLED panel. In order to allow the entire OLED panel to display full-color images, pixel units in the panel must display different colors. Currently, OLEDs mainly adopt red, green and blue (RGB) light emission layers (EML) to achieve better luminous efficiency. The evaporation technique is mainly applied in the film forming process of OLED material of the RGB EML. In the film forming process, a fine metal mask (FMM) is adopted for evaporation, and a red OLED material, a green OLED material and a blue OLED material are evaporated in different pixel units of the OLED panel side by side.